100 U.S. NATIONAL MUSEUM BULLETIN 223 



much experience, decided that it is not polygamous. "Although 

 parasitic on other Finches, especially Estrilda, I have never seen more 

 than one female with a male, when the former are laying. I have 

 seen the female accompanied b}^ the male enter the nest of an Estrilda, 

 deposit its egg, and then fly off with the male. Most of the so-caUed 

 females accompanying the males when these birds 'flock' are young 

 males and a few young females." J. Vincent (1936, pp. 113-114) was 

 unable to decide whether the species is polygamous or not "for of 

 the three or four drab looking companions to a male in breeding 

 season . . . thought to be females were often immature males which, 

 although apparently a year or more in age, have not yet developed 

 breeding dress." Lynes (1924, p. 678) suspected that the males do 

 not acquire breeding plumage in their first year "and that the harems 

 or polygamous habit commonly attributed to these birds will prove 

 to be merely the same hanging-on of first year, i.e., immature birds 

 of both sexes, but it will require proof." 



My own experience, based on study of a large number of these small 

 "flocks" during the breeding season, leads me to conclude that the 

 pintail is usually monogamous. I have never seen two courting full 

 plumaged males in any one of the breeding season flocks. Chapin 

 (1954, pp. 573-577) believed that the males are promiscuous rather 

 than polygamous. 



Jackson (1938, pp. 1525-1528) gave a valuable summary of his 

 long experience with the pintail in Kenya and Uganda as follows: 



There is, or was, a very widespread conviction tliat this bird and the majority 

 of, if not all, the long-tailed Viduinae are polygamous. . . . personal observa- 

 tions extending over a period of thirty-two years have led me to the firm belief 

 that not one of those found within Kenya Colony and Uganda is polygamous. 

 . . . Between the breeding seasons, and even during them, flocks of half a dozen 

 up to sixty or more may be met with. The great majority are either females or 

 young male birds, in the striped plumage, and it is extremely difficult, even with 

 binoculars, to tell one from the other. 



In such flocks there are generally one or more adult male birds in worn full 

 plumage, some with or without the long black tail, while others have a black 

 tail, but otherwise still in the striped dress of the female. At such times these 

 adult males may be seen dancing and pirouetting in the air above the birds 

 feeding on the ground, in the same manner as courting but with less persistence. 



Occasionally a bird in striped dress and with no sign of the black tail will follow 

 suit, and it has often occurred to me that it is not improbable that the older 

 birds are showing the younger ones how it is done. Anyhow it is obvious that 

 they are not courting, and yet it is quite conceivable that their dancing amidst 

 a large flock has added weight to the assumption that the bird is polygamous. 



During the breeding seasons, between April and June and in November and 

 December, if a cock-bird in full dress is seen by himself within a limited area of 

 a few acres in extent, it may safely be assumed that it is a breeding bird, although 

 there is no sign of its mate. He will fleck and fossick about from bush to bush 

 or other coign of vantage, and will attack furiously any other bird of more than 

 double its size and weight that may venture to show itself within its domain. 



